3D printing might be exciting and all, but it's only really good for making new items from scratch; what if you want to reapir something instead? Enter 3D painting, GE's new baby which could be used to fix up anything that's made of metal.

Formally known as 'cold spray', the technique sprays metal powders at high velocities to add material to existing objects. Amazingly, the speed at which the material hits the object is enough to help it adhere—there's no high temperature or pressure required to build up layers of metal onto the object in questions. Anteneh Kebbede, from GE, explains:

"[W]hat’s particularly exciting about cold spray as an innovative, 3D process is that it affords us the opportunity to restore parts using materials that blend in and mirror the properties of the original part itself. This extends the lifespan of parts by years, or possibly by decades.”

In theory, 3D painting is only limited by the spread of its spray, too, so it should be possible to repair even quite large structures using the technique, and unlike methods such as welding or soldering, it's much safer because it all happens at room temperature. Now, someone just needs to work out how to ship this stuff in a can. [GE]